Hi, I think ths is a real bug, because in th real world all need to refresh data in grid, but anyway... When I reload data in the grid, grid resets all expanded subtrees to collapsed state. Why I need to remember grid state each time I need to refresh data? And what I need to do to save state and load it back to the grid? Coud you provide source code which will save all expanded subtrees to expand them when data will be reloaded.